var isPalindrome = function(s){
  s = s.toLowCase().replace(/[\W_]/g,"");
  if(s.length < 2){
    return true;
  }
  let left = 0,
      right = s.length - 1;
  while(left < right){
    if(s[left] !== s[right]){
      return false;
    }
    left++;
    right--;
  }  
  return true;
}